At restaurants and cafeterias, consumers have grown accustomed to seeing a line of waste containers for recycling glass, plastic and paper items. Important as those bins are for reducing the burden on landfills, they overlook a major source of waste: the food left on diners’ plates.

Food accounts for about one-third of the trash Americans throw away, and most of it ends up in landfills. While food is generally more biodegradable than some of the other items in your trash can, it’s not environmentally harmless. Decomposing food produces methane, a greenhouse gas that is 22 times more effective at trapping heat than carbon dioxide.

In an effort to reduce those impacts, UW-Madison has launched a project to collect and compost food waste from campus eateries. Organized by We Conserve, a university-wide program that promotes environmental stewardship practices, the project aims to compost more than 400 tons of food waste annually when fully implemented.

“UW has been composting for years with other organic materials, but we’ve found that great synergy can exist by adding food. It can really improve the quality of the compost product,” says Faramarz Vakili, program director for We Conserve.

Food-collection stations are now in place at Grainger Hall and in the kitchens at Memorial Union, which prepares food for all Union delis on campus. Spoiled and unused food from both sites is taken to CALS’ West Madison Agricultural Research Station, where superintendent Tom Wright oversees the composting process.

Wright says the project has presented some challenges, particularly in educating consumers about how to sort food for composting. “Not all foods belong in a compost heap, especially meat and dairy products. So it’s important that discarded food wastes are separated to keep out things that don’t decompose well,” he says. To help guide consumers, We Conserve constructed a food-collection station at the Grainger café that uses signs and pictures to designate the proper containers for different kinds of food. Vakili says the station has helped boost the number of people participating in the project, and he’s confident that diners will catch on and embrace food sorting in time.

“Effective composting takes time and effort, and while we would love everyone on campus to create their own, that’s just not possible,” says Wright. “So this program is making it easy for them. All they have to do is give us their food, and we will do the work.”